Look Out Hubble And Webb, Here Comes Roman

By John Oncea, Editor

The Nancy Grace Roman Telescope is set to launch by May 2027. Learn more about this engineering marvel, as well as the scientific pioneer after whom it was named.

Nancy Grace Roman, Ph.D., passed away in Germantown, MD, on December 25, 2018, after a long illness at 93. Roman was, according to her obituary, a graduate of Swarthmore College and the University of Chicago. She was born in Nashville, TN, and moved to Baltimore, where she attended junior high and high school. She lived there for five years before heading to college, eventually settling in the Washington, DC, area in 1955.

Between the fifth and sixth grades, Roman organized an astronomy club to study the constellations. By seventh grade, she decided she wanted to be an astronomer and, understanding it was going to take her another 12 years of schooling, remained committed to the idea, figuring she could teach high school physics or math in high school if her dream of being an astronomer didn’t come true.

Roman heard about a job in Washington at the U.S. Naval Research Laboratory working in radio astronomy and decided it had a lot of possibilities for galactic structure, something she was interested in at that time. She spent three years there, working in radio astronomy, geodesy, and even the propagation of sound underwater, eventually becoming head of the microwave spectroscopy section of the radio astronomy program.

Over the next five years, Roman developed an international reputation as an astronomer and even became the first civilian to visit Armenia at the start of the Cold War when she spoke at the 1956 dedication of the Byurakan Observatory. This raised her visibility in the U.S., and she was asked to speak about the trip in a series of astronomy lectures which, in turn, led to a job offer from NASA.

“A few months after NASA was formed, I was asked if I knew anyone who would like to set up a program in space astronomy, Roman said. “I knew that taking on this responsibility would mean that I could no longer do research, but the challenge of formulating a program from scratch that I believed would influence astronomy for decades to come was too great to resist.”

Roman became the first Chief of Astronomy in the Office of Space Science at NASA headquarters and the first woman to hold an executive position at NASA. Her efforts were crucial in transforming the initially skeptical ground-based astronomical community into supporters of space-based astronomy. She implemented the policy that NASA would oversee major astronomy projects for the benefit of the wider scientific community, rather than leaving them as separate experiments managed by academic researchers.

Throughout her 21-year career at NASA, Roman served as Chief of Astronomy and Solar Physics at NASA (1961 – 1963), overseeing the development of the Orbiting Solar Observatory (OSO) program, developing and launching OSO 1, and developing OSO 2 and OSO 3. She held various other positions with NASA, including Chief of Astronomy and Relativity.

Roman also led the Orbiting Astronomical Observatories (OAO) program and oversaw the development and launch of the three small astronomical satellites and four geodetic satellites. She planned for other smaller programs such as the Astronomy Rocket Program, the Scout Probe to measure the relativistic gravity redshift, programs for high energy astronomy observatories, and other experiments on Spacelab, Gemini, Apollo, and Skylab.

“As the chief of NASA's astronomy and relativity programs, I was involved with planning a program of satellites and rockets with the advice of a wide sample of the nation's astronomical community,” Roman said. “I also administered a significant program of grants to support this astronomy, in both its execution and the understanding of its results.”

Roman’s final project was, according to ESA/Hubble, “making the Hubble Space Telescope a reality. In the mid-1960s, she set up a committee of astronomers and engineers to envision a telescope that could accomplish important scientific goals. She convinced NASA and Congress that it was a priority to launch the most powerful space telescope the world had ever seen.” Because of this Ed Weiler, Hubble’s chief scientist until 1998, called Roman “the mother of the Hubble Space Telescope.”

At a time when few women worked in the physical sciences, she was a pioneer who served as a role model for many girls wanting to pursue scientific careers. “Throughout her lifetime, Roman tirelessly advocated for new tools that would allow scientists to study the broader universe from space,” writes ESA/Hubble. “She left behind a tremendous legacy in the scientific community when she passed away (and in her honor) NASA has named its next-generation space telescope currently under development” after her.

The Nancy Grace Roman Space Telescope – or Roman, for short – is set to launch by May 2027 in its search for extra-solar planets using gravitational microlensing, along with probing the chronology of the universe and growth of cosmic structure, with the end goal of measuring the effects of dark energy, the consistency of general relativity, and the curvature of spacetime.

The Telescope Behind The Name

Both the Hubble and James Webb Space Telescopes have been spoiling us with incredible data and images, helping researchers make out-of-this-world discoveries. Soon, Roman – which will have a field of view at least 100 times larger than Hubble’s and may be able to measure light from a billion galaxies in its lifetime – will join them.

According to Ethdan.me, “The journey toward the Nancy Grace Roman mission began in 2009, with extensive planning and development. After a lengthy survey and development process, the mission is now scheduled to launch in May 2027. Once in space, the Roman mission will amass an incredible amount of data – 20 petabytes, equivalent to 20,000 terabytes. This vast data will contain trillions of individual measurements of stars and galaxies, providing scientists with an unprecedented wealth of information.”

Roman’s stated mission includes settling essential questions in the areas of dark energy, exoplanets, and astrophysics and it will be able to block starlight to directly see exoplanets and planet-forming disks and complete a statistical census of planetary systems in our galaxy.

“Roman will work in tandem with NASA observatories such as the James Webb Space Telescope (JWST) and Chandra X-ray Observatory, which are designed to zoom in on rare transient objects once they’ve been identified, but seldom if ever discover them,” said Julie McEnery, Roman’s senior project scientist at NASA’s Goddard Space Flight Center in Greenbelt, MD. “Roman’s much larger field of view will reveal many such objects that were previously unknown. And since we’ve never had an observatory like this scanning the cosmos before, we could even find entirely new classes of objects and events.”

The High Latitude Time-Domain Survey’s mission is well-designed to discover a specific type of exploding star that astronomers can use to trace the evolution of the universe and probe explanations for its accelerated expansion. Additionally, this survey will capture sporadic events such as stellar corpses colliding and stars being swept into black holes, as it repeatedly observes the same large vista of space beyond our galaxy. Over two years, the survey will monitor the same patch of sky about every five days. By stitching these observations together, scientists will be able to create movies that reveal a wealth of transient events.

Roman, JWST, And Hubble

There are similarities between the three space telescopes but combining Roman’s large view with Hubble’s broader wavelength coverage and Webb’s more detailed observations is what is exciting researchers.

“The Hubble and James Webb Space Telescopes are optimized for studying astronomical objects in-depth and up close, so they’re like looking at the universe through pinholes,” said Aaron Yung, a postdoctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who led the study. “To solve cosmic mysteries on the biggest scales, we need a space telescope that can provide a far larger view. That’s exactly what Roman is designed to do.”

While Roman follows JWST chronologically it is more similar to Hubble according to Dr. Becky’s YouTube video. “The Roman Space Telescope can claim a similar wavelength range to Hubble focusing on red and near-infrared light and its mirror is even the same size as Hubble’s. But Roman has been designed to look at a much bigger area of sky in a single observation so its field view is 100 times greater than Hubble’s widest exposure.”

Roman’s larger field of view will be advantageous as it creates a 3D map of the universe by surveying the sky, taking many pictures, and marking the positions of galaxies in those parts of the sky. It also has a spectrograph on board which will provide a spectrum from each of those galaxies. These spectra split the light to get a trace of how much light is at each wavelength. Then, using features in those spectra, researchers will track how much the light has been redshifted by the expansion of the universe to determine which galaxies are closer as those further away will have a much larger redshift.

“The primary mirror of the Roman Space Telescope has a diameter of 7.9 feet, the same size as the mirror of Hubble but under a quarter of the weight at 410 pounds,” writes Space.com. “The mirror grants the telescope a 0.281-degree square field of view and sends light to the two main instruments carried by the Roman Space Telescope, the Wide Field Instrument (WFI), and the telescope's Coronagraph Instrument (CGI).”

Roman’s barrel-like shape will block out unwanted light from the sun allowing the WFI to measure the light from a billion galaxies over its five-year-long operation time, aiding in its investigation of dark energy. The CGI is a high-contrast coronagraph covering shorter wavelengths (575 nm to 825 nm) using dual deformable mirror starlight-suppression technology.

It is intended to achieve a part-per-billion suppression of starlight to enable the detection and spectroscopy of planets with a visual separation of as little as 0.15 arcseconds from their host stars. CGI is intended as a technology demonstrator for an exoplanet imaging instrument on a future large space-based observatory, such as the Habitable Worlds Observatory (HWO).

Getting High With A Little Help

Through extensive collaboration between NASA, research institutions, and industry partners, the telescope is poised to deliver an unprecedented wealth of data that will reshape our comprehension of the cosmos.

The NASA divisions involved in the Roman mission include the Goddard Space Flight Center, the Jet Propulsion Laboratory, Caltech IPAC, and the Space Telescope Science Institute, notes Ethdan.me.

“Additionally, scientists from various research institutions will contribute their expertise to this ambitious project. Several companies, such as Ball Aerospace and Technologies Corporation, L3Harris Technologies, and Teledyne Scientific Imaging, are also working on the mission, further highlighting the collaborative nature of this endeavor.”

The French space agency CNES, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and the Max Planck Institute for Astronomy also have joined with NASA to provide various components and science support for Roman.

Honoring The “Mother of Hubble”

The upcoming launch of the Nancy Grace Roman Space Telescope represents a significant milestone in our quest to understand the mysteries of the universe. Named after the pioneering astronomer who paved the way for the Hubble Space Telescope, this mission holds immense potential for unraveling the enigmas of dark matter and dark energy.

“Roman will paint a more vivid picture of our universe’s past and present, giving us new clues about its possible fate,” said Rebekah Hounsell, a research scientist at the University of Maryland, Baltimore County and Goddard. “Its findings could reshape our understanding of the cosmos.”

McEnery adds, “This Roman survey will provide a treasure trove of data for astronomers to comb through, enabling more open-ended cosmic exploration than is typically possible. We may serendipitously discover entirely new things we don’t yet know to look for.”

As humanity gazes skyward, the Roman mission exemplifies our insatiable curiosity and relentless pursuit of knowledge beyond our terrestrial confines.